Solutions and Mixtures - AP Chemistry

If given the solubility product constant for a salt, we can determine the solubility for the salt as well. In order to do this, we need to use an ICE table and the equilibrium constant expression.

Initial: When the salt is added to water, there are no ions initially in solution. Because the salt is a solid, its concentration is irrelevant.

Change: When one molecule of barium fluoride dissolves, one barium ion and two fluoride ions are introduced to the solution. As a result, barium ions increase by , and fluoride ions increase by .

End: The equilibrium expression for this salt is , which will allow us to calculate the solubility based on the change in ion concentration.

The solubility for barium fluoride is .

Definition of :

for .

For :

Due to the chemical formula, there will be twice as many chloride ions as lead ions.

Solve for the unknown variable:

Multiply times the given volume:

Multiply times the molar mass of :

Solubility of solid and liquid solutes in aqueous solutions can be increased by raising the temperature of the solution. Raising the temperature increases the amount of kinetic energy of the water molecules, allowing them to better interact with the solute particles and prevent the formation of a solid lattice.

Adding other solutes with similar properties will generally decrease solubility by the common ion effect, or else will not affect solubility at all. Increasing pressure will help increase the solubility of a gas in solution, but will not affect solutions that only contain solids and liquids. Note that gas solubility will also increase with decreased temperature. This is opposite to the relationship between temperature and the solubility of solids. Low temperature will reduce the kinetic energy of gases, making them more similar to liquids, while lowering the temperature of a solid will further lower its kinetic energy and decrease its similarities with a liquid solvent.

It is possible to reduce the solubility by adding a salt that increases the concentration of an ion that is created by the insoluble salt. This is called the common ion effect.

Silver chloride will dissociate into silver and chlorine ions in solution.

If sodium chloride is added to the solution, the concentration of chlorine ions increases.

This will push the equilibrium of the silver chloride dissociation to the left, thus decreasing the solubility of silver chloride.

There are some general solubility guidelines that can help you predict which salts are soluble.

1. All compounds containing ammonium, nitrate, or alkali metals are soluble.

2. Compounds with halogens as the anion are soluble. The three noted exceptions are when they are bonded to silver, mercury, or lead.

3. Sulfate compounds are soluble, except when bonded to mercury, lead, or the heavier alkaline earth metals.

is an example of an insoluble sulfate compound because the sulfate is attached to barium, a heavy alkaline earth metal.

Solubility of solids increases when temperature increases because the increased kinetic energy increases the chance that a solute molecule gets surrounded by solvent molecules. Solubility for gases decreases when temperature increases because the increased kinetic energy allows for the gas molecules to break the intermolecular forces holding them in the solution, letting them bubble out of the solvent.

In order to solve for molarity, we need to know the necessary equation to use. Molarity is given by the moles of solute divided by the liters of solution.

Since we are given the mass of potassium nitrate, we must first convert it into moles before we can solve for the molarity of the solution. Potassium nitrate has the formula . Use this to calculate the molar mass.

Now that we have the number of moles, we can solve for the molarity of the solution using the given volume:

A mixture can be filtered or otherwise separated into its individual components. In this case, we could filter out the solid yeast from the bottom of the bottle of liquid wine. However, we could not filter out the salt, sugar, or nutrients since they are chemically mixed into the water, are in the same phase. The the salt water, coffee, and nutrient water are incorrect since these are solutions.

To identify a solution, look for a homogenous mixture composed of only one phase. Thre rice, salad, and fertilizer are descriptions of mixtures: combinations of materials which can be physically separated. The only option describing a solution is the lemonade solution since the concentrate is dissolved in water, which results in a homogenous mixture. Solutions are both mechanically and chemically combined.

The solvent can be thought of as the substance present in greater amount, or the substance in which the solute is dissolved. Solvents are often liquid. The solute is the substance present in lesser amounts, and is dissolved by the solvent. In this case, the hydrochloric acid is the solvent, because it dissolves the sodium bisulfite. Because it is getting dissolved, the sodium bisulfite is the solute.

If something is soluble, it means it's dissolved in liquid. Generally, the compound associate with the liquid (l) phase label is water; everything else takes the (aq) phase. Note that all these phase labels are written as superscripts after the species they are labeling.

All of the three salts will dissolve completely in the solution, resulting in all of the ions interacting with one another.

Chloride compounds are generally soluble, but the salt is one of the notable insoluble chloride salts. When these two ions meet in solution, they will combine and precipitate out of the solution. All the other ion combinations still form soluble compounds except for , which is also insoluble.

The precipitate will be the product that is insoluble in water, so your choices are or .

Nitrate salts are always soluble in water, as are alkali metal salts such as sodium. Thus, we know that will fully dissolve.

Halide salts (such as chlorides) are soluble in water, unless they are combined with silver, lead, or mercury. In this case, the silver atom makes the halide salt, , insoluble in water. is the precipitate.

The precipitate will be the product that is insoluble in water. The products in this reaction are and .

Halide salts (such as chlorides) are soluble in water, unless combined with silver, lead, or mercury. In this case, is soluble in water.

Sulfate salts are soluble in water, unless combined with silver, calcium, strontium, barium, or lead ions. In this case, is insoluble and is, therefore, the precipitate.

Water turning to ice is not a chemical reaction, it is a physical reaction. Nothing is changing about the water molecules chemically, they're just going from a liquid state to a solid state. Burning wood is a non-reversible chemical change because the carbon in the wood is reacting with oxygen to create ash and smoke, also, energy in the form of light and heat is released. Rust is formed when iron reacts chemically with oxygen, producing the red-orange color of rust. A gas forming is a good indicator that a chemical reaction has taken place. A precipitate is also a good indicator for a chemical reaction. It may just seem like something is changing states, but the precipitate is not a solid version of one of the reactants, it's the insoluble product formed from the chemical reaction.

If something is insoluble, it means it cannot be dissolved. The phase label reserved for solids is (s). The other phase labels are: (l) = liquid; (aq) = aqueous; (g) = gas; and the (r) phase label does not exist. Note that all of the phase labels are written as subscripts after the species; for example: .

The precipitate will be the product that is insoluble in water, so your choices are or .

Nitrate salts are always soluble in water, as are alkali metal salts such as sodium. Thus, we know that will fully dissolve.

Halide salts (such as chlorides) are soluble in water, unless they are combined with silver, lead, or mercury. In this case, the silver atom makes the halide salt, , insoluble in water. is the precipitate.

The precipitate will be the product that is insoluble in water, so your choices are or .

Nitrate salts are always soluble in water, as are alkali metal salts such as sodium. Thus, we know that will fully dissolve.

Halide salts (such as chlorides) are soluble in water, unless they are combined with silver, lead, or mercury. In this case, the silver atom makes the halide salt, , insoluble in water. is the precipitate.

The correct answer is

First of all, we know this is an acid-base reaction. is the reactant base and is the reactant acid. We know that these acid-base reactions create a water and a salt. Also, we know that sulfates are soluble, except for those of calcium, strontium, and barium. As a result, is a precipitate in the reaction and water is produced.

Most salts containing halogens are soluble. Carbonates, phosphates, sulfides, oxides, and hydroxides are insoluble except for cations containing alkaline earth metals and hydroxides of calcium, strontium, and barium, which are slightly soluble.